0520029

We propose to conduct extbf{fixed-time} observations for 2x2uninterrupted INTEGRAL orbits (2x 2x233=926 ks) of thegalactic microquasar SS433 in two consecutive primary orbital eclipses near the face-on disk precession phase of the source in October 2007. The main goal is phase-resolved hard X-ray spectroscopy of the primary orbital eclipse and study its highly variable form.The phase-resolved spectroscopy is crucial to study the structure and physical parameters of hot rarefied corona at the center of the supercritical accretion disk in SS433 discoverd by previous INTEGRAL observations. Precise form of the eclipse is neededto constrain binary mass ratio in this system which is still controversial. The proposal is not associated with the AO-5 Key Program. [truncated! Please see actual data for full text]